Randolph kreter



PATENTED SEPT. 9, 1851.

KRETER. PIANOPORTE ACTION.

UNITED STATES PATENT OFFICE. p

RANDOLPH KRETER, OF NEW YORK, N. Y.

PIANoFoRTE-AoTIoN.

Specification of Letters Patent No. 8,350, dated September 9, 1851.

T 0 all whom it may concern Be it known that I, RANDOLPH KRETER, of thecity, county, and State of New York, have invented a certain new anduseful Im- ,panying drawings, making part of this specification, inwh1ch Figure 1 is a side elevation of the action with the key up; Fig.2, a like elevaltion with the key down after the string has been struck;and Fig. 3, a like elevation with the hammer held up by the re eatingcheck preparatory to the repetition o the touch.

The same letters indicate like parts in all the figures.

The object of my invention is to obtain a repeating action of the hammerwithout the necessity of allowing the key to rise to its full heightunder the finger as in Erhards action but by a much more simple andefficient action, and to this end my invention consists in theemployment of what I denominate a repeating check or tongue connectedwith a lever hinged to the hammer rail and resting on the key the underside of the hammer butt being provided with an arm (which I denominatethe heel of the hammer butt) which rests against the upper end of theface of the operating check, so that after the hammer has struck thestring instead of coming down onto the ordinary check the heel of thebut-t rests against the repeating check and it is there held in positionready to be acted upon by the lever fly with the slightest upwardmovement of the key.

In the accompanying drawings (a) represents the usual piano key, towhich is attached the usual check (6). A standard (0) which takes theplace of the regulating rail, and the lever bottom ((Z) one part ofwhich (6) is separated by a longitudinal slot to admit a regulatingwedge (f) under it which wedge is operated by a screw (g) tapped intothe standard so that by the turning of this screw the part (a) of thelever bottom to which the lever fly (h) is hinged can be elevated ordepressed to regulate the position of the lever fly relatively to thebutt (2') of the hammer (j).

The lever fly is drawn back by a helical spring (7a) against a cushionon the end of a regulating screw (Z) tapped in the upper end of thestandard by means of which the position of the fly is regulated tostrike the butt properly.

The journals of the arbor of the hammer turn in proper recesses made ina capplate (m) secured to the top of the hammer rail (10,) and this capplate is slit for some distance from the back end to permit the upperpart to spring and over it is placed a metal plate (0) one end of whichis secured with the cap to the hammer rail by screws (7)). This metalplate is notched across to admit of bending; a screw (9) with a head atthe lower end passes through the cap and is tapped into the rear end ofthe metal plate (0) so that by turning this screw the two parts of thecap-plate (m) can be drawn together or separated to close or open therecesses that form the boxes for the journals of the hammer. So far Ihave described an action which does not essentially differ from theaction in general use and to this is added my improvement.

To the under part of the hammer butt and back of the face on which thefly acts to throw up the hammer there is an arm (1') (which I denominatethe heel of the butt) the front face of which is cushioned, and restsagainst the face of what I denominate the repeating check (8) faced withleather at (t), to receive the cushion of the butt heel, and its lowerend is attached to one arm of a lever (14) hinged to the hammer rail(0)) the other arm of which has a regulating screw (w) with a block andfelt cushion (m) at its lower end which rests on the lever, so that whenthe key is depressed the upper end of the repeating check is movedforward, so that after the hammer has struck the string and is liberatedby the fly, the heel of the but-t shall be caught by the repeating checkand then held, that the fly by a very slight upward movement of the keycan again act on the butt of the hammer to repeat the act-ion. Therepeating check which is made of wood and sufficiently thin to spring isprevented from moving toofar forward by coming against the shoulder (y)of a regulating screw which passes through the hammer rail,.so that bymeans of this screw and the one (w) before described, the position ofthe What I claim as my invention and desire to secure by Letters Patentis- The repeating check or tongue connected with a lever hinged to thehammer rail and resting on the key the under side of the hammer buttbeing provided With an arm Which rests against the upper end of the faceof the repeating check substantially as and for the purpose specified.

RANDOLPH KRETER.

Witnesses:

A. P. BROWNE, G. BROWNE.

